EFFECTS OF TRIBUTYLTIN EXPOSURE IN HERMIT CRABS: CLIBANARIUS VITTATUS AS A MODEL BRUNO SAMPAIO SANT’ANNA,*yz DAYANA MOSCARDI DOS SANTOS,§ MARY ROSA RODRIGUES DE MARCHI, k FERNANDO JOSE ´ ZARA, y # and ALEXANDER TURRAz yZoology Section, Postgraduate Course in Biological Sciences, Universidade Estadual Paulista, Rio Claro, Brazil zDepartment of Biological Oceanography, Oceanographic Institute, University of Sa ˜o Paulo, Sa ˜o Paulo, Brazil §Department of Chemical and Geological Oceanography, Oceanographic Institute, University of Sa ˜o Paulo, Sa ˜o Paulo, Brazil kDepartment of Analytical Chemistry, Institute of Chemistry, Universidade Estadual Paulista, Araraquara, Brazil #Department of Applied Biology and Aquaculture Center, Faculty of Agrarian and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, Brazil (Submitted 31 August 2011; Returned for Revision 4 October 2011; Accepted 30 October 2011) Abstract —Tributyltin (TBT) contamination affects the reproductive system of many species of invertebrates worldwide. The present study was designed to evaluate the effects of exposure to TBT pollution on the reproduction of the hermit crab Clibanarius vittatus. An orthogonal experiment was designed with two treatments: contamination (with or without TBT in the food) and crab sex (males and females). The animals were reared in the laboratory for nine months, and macroscopic and histological analyses of reproductive organs were carried out after the end of the experiment. Tributyltin was recorded in exposed crabs, but no morphological alterations were detected in the gonads of males, regardless of whether they were exposed to TBT. In contrast, females exposed to TBT displayed disorganization and atrophy of their ovaries, thus directly affecting reproduction in this hermit crab species. This effect observed in female hermit crabs may harm populations located in harbor regions, where TBT concentration is high, even after the worldwide TBT ban. Environ. Toxicol. Chem. 2012;31:632–638. # 2011 SETAC Keywords —Tributyltin (TBT) Hermit crabs Gonad atrophy Pollution INTRODUCTION Organotin compounds are characterized by a tin atom linked to one or more carbon chains (Sn-C). The number of Sn-C bonds affects the properties of organotin compounds, where the maximum biological activity is attributed to tri- substituted organotins (n ¼ 3) [1,2]. Because of this biological activity, triorganotins are used commercially as biocides in many parts of the world [2]. One of these potent triorganotins is tributyltin (TBT), which was developed in the 1970s and was used in antifouling paints to prevent sessile organisms from colonizing boat hulls, increasing water friction and therefore fuel consumption [3]. Organotin compounds, similar to other organic pollutants, can accumulate in many marine organisms from plankton to vertebrates, including mammals [4]. These substances cause serious effects even in nontarget species, such as a decrease in oyster production [5], inhibition of growth in microalgae [6], reduction in fecundity and juvenile production in polychaetes [7], and development of imposex in mollusk species [8–10]. Imposex is the main effect recorded around the world; it is characterized by a superimposition of male genital organs such as the penis and vas deferens on female gastropods [11]. This abnormality has been recorded in approximately 120 mollusk species worldwide, including several that occur in Brazilian waters [8–10]. This abnormal development of male sexual characters may sterilize females, as reported by Shi et al. [12] for the prosobranch gastropod Cantharus cecillei (Philippi, 1844) in China. Because of these negative effects, TBT was regulated in many countries in the 1980s and 1990s. The regulations have been successful in reducing the toxic threat posed by TBT in many locations around the world. Thus, the International Maritime Organization proposed prohibiting all antifouling uses of TBT by 2003 and the presence of TBT on ship hulls by 2008 [13]. Despite the strictures on TBT use in many parts of the world [5,14,15] and recently in Brazilian waters [16], contamination of the environment and biota continues to be recorded [17,18], including in hermit crabs [19]. Hermit crabs are anomuran crustaceans that use gastropod shells to protect their soft and fragile abdomens from predation and environmental stress [20]. Clibanarius vittatus (Bosc, 1802) is a typical hermit crab of estuaries, the type of habitat in which the greatest concentrations of this pollutant have been recorded [2,21,22], including in Brazilian estuaries [17,19], because of the concentration of harbor activities. Different populations of this species were recorded as having high concentrations of this pollutant in the natural environment [19], and a recent study demonstrated that this hermit crab assimilates TBT mostly from food and shows a rapid depuration rate, making it a good bioindicator of recent TBT contamination [23]. In addition to their capacity to accumulate TBT and serve as an indicator of environmental pollution through measure- ment of the concentration of this pollutant in their tissues, hermit crabs may be directly affected by TBT, especially in the reproductive system. In the present study, an orthogonal experiment was designed to analyze the possible negative effects of exposure to TBT pollution in the reproductive system of hermit crabs using C. vittatus as a model. Environmental Toxicology and Chemistry, Vol. 31, No. 3, pp. 632–638, 2012 # 2011 SETAC Printed in the USA DOI: 10.1002/etc.1724 * To whom correspondence may be addressed (brunusant@hotmail.com). The present address of B.S. Sant’ Anna is Institute of Exact Sciences and Technology, Universidade Federal do Amazonas, Itacoatiara, Brazil. Published online 21 December 2011 in Wiley Online Library (wileyonlinelibrary.com). 632